Battery pack for portable computer

A computer assembly, comprising:

• a portable computer, including a battery connector;
• a first battery housing mechanically engageable with the portable computer, the first battery housing holding a first battery assembly including a first battery;
• wherein during a first period the portable computer controls a second battery assembly including a second battery housing mechanically engageable with the first battery housing and holding a second battery assembly including a second battery to supply power to the portable computer;
• wherein during a second period the portable computer controls the first battery assembly to supply power to the portable computer, such that during the second period the second battery housing can be removed from the first battery housing and engaged with an external charger to recharge the second battery while the first battery provides power to the computer;
• and
• wherein the battery connector is configured to support the first and second batteries such that no switch is needed to route communication from the portable computer to select one of the battery assemblies, wherein the first battery assembly includes a first power line switch connected to the first battery and a first battery processor controlling the first power line switch, the second battery assembly includes a second power line switch connected to the second battery and a second battery processor controlling the second power line switch, and the computer causes the processors to control their respective power line switches so that only one of the batteries at a time is connected to the computer.

A method, comprising:

• electrically engaging a first removable rechargeable battery with a portable computer;
• mechanically coupling a second battery housing holding a second battery assembly with a first battery housing associated with the first battery assembly;
• selectively routing data communication from the computer to the first or second battery assembly;
• wherein the first battery assembly includes a first power line switch connected to the first battery, and a first battery processor controlling the first power line switch;
• wherein the second battery assembly includes a second power line switch connected to the second battery, and a second battery processor controlling the second power line switch;
• and
• wherein the computer causes the processors to control their respective power line switches so that only one of the batteries at a time is electrically connected to the computer.